THE EURO5 TECH REVOLUTION
How the next tier of strict environmental regs could pave the way for supercharged 600s, widespread VVT and even a glut of hybrid sportsbikes
Stricter emissions regulations open the floodgates for supercharged sportsbikes
UNLESS YOU’VE been living in a cave for the last couple of years you’ll be familiar with the term ‘Euro 4’. The current European emissions limits for bikes came into force in two stages – newly type-approved models had to comply from the start of 2016 and carry-over bikes had to be updated to meet the limits from January 1, 2017.
For manufacturers, it’s old news; all bike engineers’ eyes are now firmly on the next-stage ‘Euro 5’ limits which represent a much bigger step. But could stricter regulations spell the end for sportsbikes – or force manufacturers to try new ideas? PB takes a close look at what Euro 5 means for new bikes. Don’t panic – it’s not all doom and gloom.
Farewell traditional 600s
Euro 4’s emissions demands have had the biggest impact on sportsbikes. Some bikes required expensive engine revisions to bring them into line, and if that model’s sales aren’t high enough to justify the investment there’s only one other course of action; they’re axed – 600cc supersport bikes in particular being decimated.
The Euro 4 regulations are tough, particularly for high-revving, high-powered, small-capacity engines. Firstly, there’s the straightforward cut in emissions limits – the latest rules slash carbon monoxide from 2.0g/km to 1.14g/km, hydrocarbons from 0.3g/km to 0.17g/km and NOx from 0.15g/km to 0.09g/km. But Euro 4 also introduces a rule that bikes must still pass the new limits after 20,000km or 35,000km (depending on engine size), compared to just 1000km under Euro 3. So a brand new engine needs to be around 30% under the legal limits to give headroom for it to deteriorate and still beat the restrictions with mileages equivalent to many years’ average use.
Screaming four-cylinder 600s rely on high revs to achieve their power, which has a couple of problems. One is that they wear more over the same mileage when compared to a lower-revving engine. Worse, they need a lot of valve overlap – the period when the inlet valve opens before the exhaust valve has closed – to operate at high revs. While it makes for clean running at peak revs, that valve overlap means emissions tend to be worse at lower revs, where the emissions are tested. It can be fixed, but only by adding expense; costlier catalytic converters, for instance. Clever engine systems like variable valve timing would make for an emissions-friendly 600, but development/build costs would be the same (or more) than a 1000cc superbike, and since sales of 600s are already slow, there’s little case to be made for middleweights costing £15,000.
So what changes for Euro 5?
So, we might be saying goodbye to traditional, screaming 600s. But superbikes are still OK under Euro 4, right? Yes. All the major manufacturers except Ducati have updated their superbikes to meet the new rules. The 1299 Panigale is being sold under the ‘end of series’ regs and will soon be replaced by a new range-topping Ducati, probably a Desmosedici-derived, 1000cc four-cylinder.
But Euro 5, like most sequels, will be rather worse than its forebears. And it’s not far away; the current plan is to bring it in for new models at the start of 2020 and to get manufacturers to make the rest of their bikes comply by January 1, 2021.
How much worse? The numbers show a relatively small cut in CO limits but a big slash in hydrocarbons, down from 0.17g/km to 0.1g/km. NOx is cut from 0.09g/km to 0.06g/km. There’s also a new limit, for non-methane hydrocarbons, at 0.068g/km (68% of the total hydrocarbons). That’s vastly less than current bikes manage and will pose an even larger problem to engines with lots of valve overlap. Like every current four-cylinder superbike...
The overlap dilemma
No, this isn’t a dire warning that the sky is falling. But superbikes in future might be quite different – in a good way.
To get a lesson on where tougher emissions limits will lead, the simplest thing is to look at the way cars have developed over the last few years. On four wheels, Euro 5 is a dim memory – today’s cars are already on even harder Euro 6 restrictions.
Modern cars widely use variable valve timing, and bikes are slowly catching up. Kawasaki’s GTR1400 has had simple, hydraulic cam-phasing VVT (which advances or retards the inlet cam timing depending on revs) for a decade. Ducati is slowly spreading similar cam phasers, on both intake and exhaust, through its Testastretta 11 twin-cylinder range. And for 2017, Suzuki has become the first to field a VVT superbike, using a clever inlet cam phaser that employs centripetal force rather than hydraulics – a system the Japanese factory has used in MotoGP to dodge regulations that ban hydraulic or electronic VVT set-ups.
So VVT is already here and will only get more widespread. It will follow in the footsteps of things like fuel injection and fly-by-wire throttles, which both were well established for emissions purposes in cars before they migrated to bikes.
Suzuki has become the first to field a VVT superbike, using a clever inlet cam phaser that uses centripetal force rather than hydraulics
Turbocharging the future
Turbos have made a massive comeback in the car world thanks to Euro 5 and Euro 6, allowing manufacturers to downsize their engines and add unprecedented combinations of performance and fuel economy. The combination of modern electronic control systems, small, light turbos and fly-by-wire means that they can be just as sharp as a normally-aspirated motor.
On the turbo front, Suzuki has so far been the most outspoken. In 2013 it showed the turbocharged Recursion concept – a 588cc parallel twin. Although it only claimed a modest 100bhp, at 74lb.ft the engine’s torque was in the superbike league. In 2015, the firm revealed a much more production-ready turbo engine. Again it was a parallel twin, but quite unlike the Recursion’s. Where that concept used a simple SOHC layout, the new engine, dubbed EX7, was a DOHC motor with larger, but still secret, capacity – the ‘7’ perhaps hinting at 700cc.
Like Kawasaki, Suzuki is expected to use the biennial Tokyo Motor Show at the end of this year to reveal the next stage in its progress towards a whole new class of forced induction bike. The firm has been open about the fact that its turbo engine is moving towards production. It’s likely that it will eventually power a whole range of models.
Car firms again – faced with their own set of ever-toughing emissions and economy targets – have jumped on to the supercharging bandwagon, creating monstrous engines with unprecedented power figure at a surprisingly reasonable cost. Chevrolet’s bluecollar Camaro can be had with a 6.2-litre
Suzuki have so far been the most outspoken on turbos, showing a 588cc parallel twin in 2013
supercharged V8 making 640bhp and 640lb.ft...
Kawasaki has spent millions on developing bike-specific supercharger technology. The Ninja H2 might be a dream bike to most, but its tech is likely to filter down to more mainstream machines in the near future. Like turbos, superchargers have the potential to make smaller, more efficient, lower-emissions engines perform as well as – or better than – today’s larger units. Despite its performance advantage, the H2's emissions ate lower than a ZX-10Rs
Future supercharged Kawasakis might well have smaller cylinder count. For instance, a mid-sized win – say 650cc, like Kawsaki’s Ninja 650/Z650 models – with a supercharger attached could be airly easily developed to make the same sort of ower and torque as today’s 1000cc superbikes, with the potential added benefit of lower weight. Kawasaki is widely expected to reveal its
second-generation supercharged bike later this year, although exactly what form it will take is still a secret. Honda, while it hasn’t shown anything officially yet, has already been working on supercharged twin-cylinder designs. The firm has filed a host of patents for supercharged parallel twins, some appearing to be based on the NC750 engine, others looking more like a VFR1200F’s V4 with the rear cylinder bank sliced off and replaced with a supercharger.
Even Norton has plans to get in on the forced induction action. The British company has engaged engine firm Ricardo to develop the 1200cc V4 in its new superbike, but is also at work on a 650cc parallel twin – effectively half the new V4, with a slight capacity stretch – which it hopes to develop to include a supercharged version.
Best of both worlds
While forced induction and VVT are the two concepts closest to making big changes to the bikes we buy, other technologies proven in cars are also making a move towards two wheels. One is hybrid power, combining a downsized petrol engine with an electric motor. While the word ‘hybrid’ evokes images of holier-than-thou arseholes driving a Prius, it’s worth bearing in mind that the latest crop of multi-million pound hypercars have all used hybrid tech in pursuit of earth-shattering performance while remaining emissions-legal. The Porsche 918 Spyder and McLaren P1 both take the same route. Again, it’s under consideration for bikes. Honda has filed several hybrid patents, although is more likely to use the system on a large tourer than a sportsbike.
Suzuki’s hybrid developments include perhaps the most extreme superbike yet – a turbocharged four-cylinder with an electric motor that helps add even more power and fills in any remaining turbo lag or holes in the powerband. Only revealed in patents so far, it shows how seriously manufacturers are taking the new technology.
Screaming fours aren’t doomed
In the shorter term, we’ll see a gradual shift towards different tech. Euro 5 in 2021 won’t instantly draw a line under four-cylinder superbikes, but it’s likely to alter the delicate balance of cost and return for manufacturers, tipping some in favour of boosted, lower-revving, smaller-capacity designs with a lower cylinder count. Far from restricting the range of options, we’ll probably see a wider choice of solutions.
Whichever solution bike makers opt to pursue, the clear lesson from the car industry is that we should ignore dire warnings of reduced performance or spiralling costs. Cars today are more powerful, more economical and offer more performance-per-pound than ever before. The same will apply to future superbikes, regardless of their engine size or layout. One day we might look back at four-cylinder, naturally-aspirated sportsbikes in the same way as we do a two-stroke Suzuki RG500 now; with warm memories but safe in the knowledge that the latest stuff is many times better.
Cars today offer more performance-per-pound than ever. The same will apply to future superbikes
The 2017 Suzuki GSX-R1000’s VVT is the first on a production superbike. But this system will gradually become more widespread
The costs involved in keeping 600s like the ZX-6R compliant simply don’t add up when you take the sales figures of supersport bikes into account
Ducati has dispensation to keep selling the non-Euro 4-legal Pani, for now...
Suzuki’s turbocharged ‘Recursion’ concept has since evolved into the DOHC ‘EX7’
Kawasaki’s supercharged, nutcase H2 is actually cleaner than the firm’s ZX-10R superbike
Honda patents clearly show they’re serious about supercharged twin-cylinder development
Suzuki’s four-cylinder turbo is planned to use an electric motor to add even more power. Hybrid bikes? Yes please...